A WBEZ analysis released last week showed Ellison has quickly become the best-scoring high school in this needy part of town, where test scores are dismal.

The analysis also showed the city’s new schools—including charters and turnarounds that Emanuel has touted—are a mixed bag.

"I’m glad we have that study," Emanuel told reporters today. "Charters are not the end-all and be-all. They’re not. They are a tool in the tool box. And those that succeed—let’s invest more. Those that don’t—either improve or we terminate ‘em."

Chicago has spent millions, closed schools, fired teachers, and moved students to create its 103 new schools.

WBEZ’s analysis showed vast differences in success even within charter school networks. Chicago International Charter Schools, which runs Ralph Ellison, runs other schools that are not beating out nearby neighborhood comparison schools.

"Education is hard," said Beth Purvis, director of the CICS network. That's true for all types of schools, she said.

Emanuel says it was a coincidence that his first school visit as mayor-elect was to a charter school, though he praised Ralph Ellison for instilling hope in students and helping them get to college. Emanuel said he ended up at Ellison because during his mayoral campaign, he met a teacher from the school. He taught her Advanced Placement Government class Friday.

Emanuel says he and his wife have not yet decided where they'll send their own children to school. "We’re looking at public and private schools," said Emanuel. "And we’ll make what’s in the interest of our individual children. If it comes with a political price, I’m willing to pay it.